Lowestoft and Great Yarmouth regional Astronomers based in Lowestoft and Kessingland Astronomy group which is part of Lyra based in Kessingland

Total Pageviews

Monday, 22 July 2013

SPA ENB No. 357

The SOCIETY for POPULAR ASTRONOMY

Electronic News Bulletin No. 357 2013 July 21

Here is the latest round-up of news from the Society for Popular Astronomy. The SPA is Britain's liveliest astronomical society, with members all over the world. We accept subscription payments online at our secure site and can take credit and debit cards. You can join or renew via a secure server or just see how much we have to offer by visiting http://www.popastro.com/

HUBBLE DISCOVERS A NEW MOON AROUND NEPTUNE NASA

The Hubble telescope has discovered a new satellite -- the 14th -- of Neptune. Designated S/2004 N 1, is estimated to be no more than 12 miles across, making it the smallest known moon in the Neptunian system. It is so small and dim that it even escaped detection by the Voyager 2 spacecraft when it flew past Neptune in 1989 and surveyed the planet's system of moons and rings. Astronomers found the moon on July 1, while studying the faint arcs, or segments of rings, around Neptune. It has a circular orbit, and completes one revolution around Neptune every 23 hours.

STEAM OBSERVED ON EXTRA-SOLAR PLANET RAS

Since the early 1990s scientists have found almost 1000 'exo-planets' in orbit around other stars. They are mostly much larger than the Earth, and many are much closer to their stars than we are to the Sun, leading them to be described as 'hot Jupiters'. Now astronomers have detected the spectrum of water molecules in the atmosphere of one of them. They looked, with an infrared spectrometer called CRIRES on the VLT in Chile, at the exo-planet HD 189733b, that orbits its star every 2.2 days and is heated to over 1000蚓. Astronomers usually do not see the actual exo-planets, but infer their existence by measuring their gravitational influence on the stars about which they orbit, a reflex motion that is only a matter of metres per second. In this case, however, the team, led from Leiden University, managed to measure the velocity of the planet itself, about 110 km/s, even though it is nearly a thousand times fainter than the star, by observing water molecules in its spectrum. It seems likely that some other exo-planet atmospheres will also be detectable in the same way.

HUBBLE SEES A BLUE PLANET NASA

Astronomers working with the Hubble telescope have deduced that the planet HD 189733b, referred to in the preceding item and one of the closest exo-planets that can be seen in transit cross the face of its star, is cobalt blue in colour. If seen directly, that planet would look like a deep blue dot, reminiscent of the Earth as seen from space. Although the planet resembles the Earth in terms of colour, it is not Earth-like, being only 2.9 million miles from its parent star and dreadfully hot. In 2007, the Spitzer space telescope managed to measure the infrared heat from the planet, leading to one of the first temperature maps for an exo-planet. The map shows day-side and night-side temperatures to differ by about 300蚓. That difference could be expected to cause fierce winds to roar from the day side to the night side. It would not be a homely place to live.

ALMA OBSERVES STAR-FORMING REGION ESO

The most massive and brightest stars in the Galaxy form within cool dark clouds, which make it difficult to see exactly what is happening. One such cloud is called Spitzer Dark Cloud (SDC) 335.579-0.292; it is about 11,000 light-years away. ALMA observations, made with just a quarter of the eventual complete array, show details of the motions of the filamentary network of dust and gas, and indicate that a lot of gas is flowing into a central compact region. The cloud is thought to have a mass of over 500 times the mass of the Sun and is still growing. It is is expected eventually to give birth to a brilliant star with up to 100 times the mass of the Sun.

A LOT OF DUST AROUND SUPERNOVA 1987A RAS

Surprisingly low temperatures detected in the remnant of the supernova 1987A may help to explain why space is so abundant with dust grains and molecules. In 1987, an explosion of a massive star occurred in the Large Magellanic Cloud, 'only' 170,000 light years away. 25 years later, astronomers have used the Herschel space observatory and ALMA to study the supernova remnant. They found unexpectedly cold molecules and dust. The explosion observed in 1987 scattered elements made by the star into space in the form of a very hot plasma. The gas has now cooled to temperatures between -170 to -250 degrees Celsius. That is surprisingly cold, comparable to the icy surface of Pluto at the edge of the Solar System. The gas has formed molecules and some has even condensed into solid grains of dust. The Herschel observations show that the supernova produced dust and solid material equal to about 3/4 of the mass of the Sun. Previously, scientists have believed that supernova remnants contain only very energetic atomic gas, detectable at X-ray wavelengths.

OPPORTUNITY'S IMPROBABLE ANNIVERSARY NASA

The 'Opportunity' rover on Mars was designed only for a 3-month mission on the hostile Martian surface. Yet on July 7 there was celebrated the tenth anniversary of its launch and more than 9 years on Mars. The rover is currently en route to 'Solander Point', a place on the rim of Endurance Crater where interesting-looking areological layering is exposed for investigation. After nine-plus years of travelling, Opportunity recently set the record for the US space programme's mileage on another planet. That occurred on May 15, when the rover drove 80 metres, bringing its total distance to 35.76 km. The previous mark had been held by the Apollo 17 moon rover, which astronauts drove for 35.74 km across the lunar surface in 1972.

Solander Point, where Opportunity is heading now, has two main attractions. First, it has a thick series of strata to look at, and secondly, there are north-facing slopes where the rover can tilt its solar panels toward the Sun and hope to ride out the coming winter. The minimum-sunshine days of this sixth Martian winter for Opportunity will come next February. If Opportunity survives another year, the rover might yet break the 40-year-old all-time extra-terrestrial driving record set by Lunokhod 2, a Soviet robotic vehicle that travelled an estimated 42 km across the Moon in 1973.

DOUBLE-SIZED SUCCESSOR PLANNED FOR LIVERPOOL TELESCOPE RAS

A successor to the present largest fully robotic telescope is being planned. The Liverpool Telescope (LT) is a 2-metre optical telescope that has been in operation on La Palma since 2004. A useful feature has been its ability to react quickly to newly discovered or transient events, such as gamma-ray bursts (GRBs). It has also been used by more than 2000 schools as an 'outreach programme'. Now, the community is being consulted on its successor, LT2. Plans for it are being developed by the Astrophysics Research Institute of Liverpool John Moores University, which owns and operates the LT. LT2 will be a 4m-class telescope, and the preferred location is again La Palma.

Like the existing telescope, LT2 will be fully robotic and will be able to make rapid and flexible observations to capitalize on discoveries made elsewhere. That will become increasingly important as more large-scale surveys begin. From around 2020, the 'Large Synoptic Survey' telescope is hoped to survey the entire southern sky every few nights; but it seems not to have been noticed that that will be rather at cross purposes with LT2, which will not be well placed to follow up on southern objects. All the same, it is claimed that LT2 will be able to slew extremely rapidly to a new object very soon after receiving a 'trigger' from elsewhere, in order to catch the light from transient objects that fade extremely rapidly, like GRB after-glows. The aim is for LT2 to be able to set on the object and start making follow-up observations in only about a minute. There will evidently be scope for the appointment of a ruthless administrator who will have a particular interest in that sort of object and be in the fortunate position of being able to give over-riding priority to it. The interests of the poor observer whose work may be fatally compromised when the telescope is suddenly snatched away without any warning will presumably take a back seat.

We wonder whether Solar Cycle 24 has reached its maximum. From the observations by Section members in June, when a record of solar activity was made for each day, the Mean Daily Frequency, MDF, for Active Regions was less than that for May, down to 3.59 from 5.39. Also, the Relative Sunspot Number, R, was down to 46.61 from 72.77.

WHITE LIGHT The SH was more active than the NH by a factor of about 2. The maximum AR count of 8 was on the 23rd and the highest R number was 103 on the 18th and 20th. The month began and ended with 4 ARs visible, and the maximum AR numbers and sunspots were from the 16th to the 23rd with a surge of activity, a group of ARs with 5 SH/2 NH, 8 on the 23rd 6/2. No blank discs were seen, nor large ARs. MDF 3.59 R 46.61

H-ALPHA Compared to the decline in white-light activity, prominence activity remained about the same as in May. Some were visible daily, as were filaments and areas of plaging to larger ARs. A large W-limb prominence had a bright, detached part on the 9th. Other large prominences occurred on the 7th, 13th, and 16th. A NH flare was seen on the 2nd, E of the CM. MDF 7.78

The full Report, plus images, can be viewed on the Solar link from the SPA home page.

Bulletin compiled by Clive Down

(c) 2013 the Society for Popular Astronomy

--

Good Clear Skies--Astrocomet--Colin James Watling

--

Various Voluntary work-Litter Picking for Parish Council (Daytime) and also a friend of Kessingland Beach (Watchman) --

--Real Astronomer and head of the Comet section for LYRA (Lowestoft and Great Yarmouth Regional Astronomers) also head of K.A.G (Kessingland Astronomy Group) and Navigator (Astrogator) of the Stars (Fieldwork) --Information -- And More Info

No comments:

Astrocomet

I started in Astronomy in 1997 when the Comet Hale Bopp got me interested in Astronomy and Skywatching, since then I have joined Lyra and have vastly improved my knowledge of this very rewarding science.